The answer came in this morning's local newsflash.
He was found dead in his truck. It had veered off a well traveled road into a ravine at the side of it. I should point out that a ravine here is only a depression big enough to possibly hide a car's presence. He most likely was drunk, fell asleep and caused his own accident or he had a heart attack and lost control of the vehicle. What I find somewhat odd is, how long it took to find him. It might have made the difference of life or death if he were only injured. The heat of these last few weeks would have finished him.
He was driving a bright red GMC Yukon, the road he was on would have been the route home and where he was found, the first leg of it. Given the extent of effort to find him via the flyers.. his vehicle had not been located, I would think that something like this might have been suspected and signs of a disturbance in the foliage or tracks in the median, if there were any, along the side of the road checked. The car was spotted by a passerby. Sad ending.